fun setTag(tag: ExifTagInfo): ExifTagInfo
Puts an ExifTag into this ExifInterface object's tags, removing a previous ExifTag with the same TID and IFD. The IFD it is put into will be the one the tag was created with in #buildTag.
tag - ExifTagInfo: an ExifTag to put into this ExifInterface's tags.
Return
ExifTagInfo: the previous ExifTag with the same TID and IFD or null if none exists.